Controlling mechanism for refrigerating apparatus



June 14, 1932. J. R. REPLOGLE 862635 CONTROLLING MECHANISM .FORREFRIGERATING APPARATUS Filed Feb. '7. 192'? UNITED STATES PATENT oFFlcEy JOHN `R.'REPLOGLE, OF DETROIT, MICHIGAN, ASSIGNOR TO KELVINATORCORPORATION, l

0]? DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN A-CONTIR( )LLINGMECHANISM FOR REFRIGERATING APPARATUS Application led February 7, 1927.Serial No. 166,277.

This invention relates to automatic control mechanism for` artificialrefrigerating systems. j

Anobject of my invention is to maintain a predetermined range of lowtemperature in a chamber to' be cooled with an artificial re,-frigerating system in .which the power appliance is automaticallycontrolled by mechanlsm responsive to the-temperature of the 'nrefrigerant in the low side.

' Another object of my invention is to lprovide Ia fluid pressure devicewhich isresponsive to the temperature ofthe refrigerant in the low sideof an artificial ref rigerating sysn'i tem t aiectmechanism associatedto control the operation of the power appliance.

parent as the description progresses, in which likeV charactersdesignate like parts in the accompanying drawlng illustrating a`preferred embodiment of the invention.

Inthe drawing-r' F'g.'1 is a fragmentaryjsectional view ofa cooling unitincluding a brine tank and evap-` es-,orator showing my inventionassociated therewith.

\ Fig. 2 is a front elevational view of the Same showing the controlandrefrigerant l conduits associated therewith, and

3o Fig. 3 is a diagrammatic view of anartificial refrigeratlng systemincorporating the invention. Y

My invention lis associated with a refrigerating system of conventionalconstruction sor-condenser unit A, and a power appliance or motor M.

. The cooling unit of the refri erating Lsystem includes a brine tankl() an an evapora- 4'0 tor 11 supported interiorly thereof, the ysaidevaporator "structure including a header 12 and depending 'pipe loopsV13 secured to the header and in open communication therewith, one endof the evaporator header being closed 45 Vby the endplate 14. One wallof the brine tank is provided with a large opening 15, the closure plate16 being secured to the brine tank by the bolts17 to close the opening.The end late 14 `of-the evaporator is secured 60 to the c osure plate,the entire evaporator v the casing 23 surmounting the compressor- Theseand other objects will be more ap v circuit between the evaporator andcompreswhichcomprises a cooling unit B,- a compres structure beingremoved and inserted as a unitary structure through the large openinginthe wall of the brine tank. The end plate of the evaporator header isprovided with refrigerant inlet and outlet passages 18 55 and 19respectively, suitable float controlled,

valve lmechanism 20 being associated with the inlet passagetoautomatically maintain a substantial constant quantity of liquid -refrigerant Withinthe evaporator and suitable valved couplings 21 areconnected with these inlet and outlet passages. A refrigerant feedconduit 22 connects the lcoupling adjacent said inletxpassage 18 with areservoir for the condensed refrigerant interiorly of condenser unit Aand the refrigerant return conduit 22a connects the crankcase 24 of thecompressor with the coupling adjacent the outlet passage 19, thuscompleting a closed 70 Sor, and the evaporator and refrigerantreservoir.

"The mechanism for controlling the operat1on of the system comprises apressure controlled switch actuating mechanism 33 and thermal responsivemeans D connected there-- with which is associated with the low side ofthe refrigerating system.' The thermal responsive means includes areceptacle 25, prefsu e'rably a long copper tube, which is secured tothe inner face of the end plate and extends interiorly of theevaporator. This tube is closed-"at its inner end by the plug 26 and isadapted to contain a heat responsive iuid that will expand whensubjected to a rise in temperature. The interior of said tube is in opencommunication with the passage 27 through vthe end plate 14, and afitting 29 is securedto the exterior face of the end plate, said fittingbeing provided with a passage 30 in open communication with the passage27 and the interior of the tube. A conduit 32 connects the passage 30with the pressure 95 controlled switch actuating mechanismy 33.A Theparticular form of switch mechanism forms no part of they presentinvention, and

is fully described in my (zo-pending application Serial No. 475,344,filed June 6, 1921,v 10o which has matured into Patent No. 1,823,002,dated September 15, 1931.

A rise in temperature within the evaporator will affect the fluid withinthe recep` tacle or tube 25, thereby increasing the pressure of thefluid, the eect of this increased 1 pressure being transmitted throughthe comperature of the evaporator within a predetermined range.

As stated above, the fluid in the tube should be responsive totemperature changes and should expand when subjected to increasedtemperatures. Various fluids may be used in the tube, but I prefer touse the same heat responsive fluid within the tube which is used as therefrigerant in the refrigerating sys- .tem, for the reason that similarpressure con` ditions may be had within the tube as inthe evaporator,thereby giving more accurate results and permitting the accuratemaintenance of temperatures in the evaporator within a predeterminedrange. j

I find it convenient to charge the tube with refrigerant taken from theevapora-tor. To accomplish this, the tube is inclined downwardly, theinner end of thetube being submergedl in the refrigerant. The plug thatclosesthe inner end o the tube is provided with a passage 40, andadjustably supports the valve 41 for closing the passage 40. The valveis carried by the valve stem 42 which extends interiorly of the tube andthrough the packing 43 into a chamber interiorly of the fitting 29.Access may be had to the valve stem by removing the plug 44, the end ofthe valve stem being shaped to permit the application of a wrench. vThusthe passage 40 may be opened to permit refrigerant to flow into the tubeby manually turning the valve stem, thereby unseating the valve carriedby said valve stem. The valve is closed whenthe proper amount ofrefrigerant hasbeen admitted to the tube. lVith such a construction itis possible to recharge the tube with expansible fluid whenevernecessary.

It will be noted that the mechanism described above permits themaintenance of predetermined range of low temperature in a chamber to becooled. Temperature changes within said chamber affect the temperatureof the refrigerant within the evaporator, causing vaporization of theliquid refrigerant and an increase in pressure therein. The temperatureof the fluid in the tube extending interiorly of the evaporator iscorrespondingly affected, the rise in temperature causing the fluid tovaporize, thereby causing a corresponding increase in pressure.v Whenthe pressure of the fluid reaches a predetermined maximum the powerappliance is started in operation, the compressor operated therebywithdrawing vaporized refrigerant from the evaporator thereby reducingthe pressure and temperature of the refrigerant in the evaporator, thetemperature and pressure of the fluid in the tube being likewiseaffected. When the pressure of the fluid in the tube reaches apredetermined minimum, the power appliance is stopped.

The tube 25 is preferably submerged in the refrigerant to obtain a moredirect thermal contact between the refrigerant in the evaporator and thefluid in the tube. lThe separate enclosed control means is solelyresponsive to temperature changes within the chamber to be cooled, andbecause of its location and the character of the fluid contained therein', a very accurate and sensitive control may be had of theoperation of the refrigerat'ing apparatus.

Various changes can be made in the type of heat responsive structureshown, and other details of the control mechanism, without departingfrom the spirit of my invention and the scope of what is claimed.

I claim:

1. The combination with an artificial refrigerating apparatus suppliedwith power including a refrigerant evaporator of a temperatureresponsive device for controlling the operation of the apparatus,comprising: an elongated tube disposedwithin the evaporator and havingone end vsecured to a. wall thereof and connected to the power supplyfor the apparatus, means at the opposite end of the tube for admittingrefrigerant from the evaporator to the tube and means for controllingsaid latter means.

2. The combination with an artificial refrigerating apparatus suppliedwith power including a refrigerant evaporator of a temperatureresponsive device for controlling the operation of the apparatus,comprising: an elongated tube disposed within the evapora.- tor andhaving one end secured to a wall of the evaporator and connected to thepower supply for the apparatus, a valve at the opposite end of the tubewhereby refrigerant may be admitted thereto, and means projecting fromthe first mentioned end of the tube for operating the valve. Y

3. The combination with an artificial refrigerating apparatus suppliedwith power including a refrigerant evaporator of a temperatureresponsive device for controlling the operation of the apparatus,comprising: an elongated tube disposed within the evaporator and havingone end communicating with a passageway in the head and connected tosignature.

Lacasse frigerating apparatus supplied with power y including arefrlgerant evaporator of a temperatue responsive device for controllingthe operation of the apparatus, comprising: an elongated tube disposedwithin the evaporator and having one end secured to a wall of theevaporator and connected to the posite end of the tube Wherebyrerigerantmay be admitted thereto, and means operable exteriorly of the evaporatorfor opemng and closing the valve. i

In testimony whereof I hereunto aix my JOHN R. REPLOGLE.

powersupply for the apparatus, a valve ower .supply for the apparatus, avalve at t e op-

